A well proven method for creating a 3D image is to cause a viewer to see different perspective views of a scene with each eye. One way to do this is to display two differently polarized images on a screen, and for the viewer to wear corresponding polarizing filters on each eye.
An autostereoscopic display or a three dimensional (3D) display may be implemented using an aperture or slit array in conjunction with a two dimensional (2D) display to display a 3D image. The principle of the device is that when looking at a 2D image through a slit array, the slit array separated from the screen by a distance, the viewer sees a different part of the 2D image with each eye. If an appropriate image is rendered and displayed on the 2D display, then a different perspective image can be displayed to each eye of the viewer without necessitating them to wear filters over each eye.
One important parameter which governs quality in most 3D display technologies is the number of perspectives that can be presented by a 3D display. This leads to challenges in calculating image information to give sufficient animation rate. The system cost may be reduced if calculations can be performed using standard graphics processing units.
Further, autostereoscopic displays give rise to image distortions for virtual scenes that extend in front or behind a central display plane. These are the result of a number of factors, many related to the fact that a continuous scene is represented with a device which is discrete. Examples of image distortions include lines becoming jagged, which may be referred to as tearing, and thin vertical features or other small features disappearing.
Known rendering methods do not minimise image distortions in an effective way. They may optimize the rendering for a set number of viewing positions. This means that image distortions will accumulate in certain observation positions. Viewers of a display will move freely so it may be advantageous if discontinuities are spread evenly.
Known rendering methods require significant hardware resources, typically graphics processing units, and may give rise to slow image update. This may be overcome by using additional hardware resources, which in turn leads to higher cost.